Did some more Lopunny testing, found a set I really like.
Lopunny (F) @ Lopunnite
Ability: Limber
Happiness: 0
EVs: 96 HP / 252 Atk / 4 Def / 156 Spe
Jolly Nature
- High Jump Kick
- Frustration
- Baton Pass
- Fake Out
This set is honestly brutal in how efficiently it dismantles offensive teams. The EV spread is pretty simple - maxed attack, enough speed for jolly Weavile (since it's only a couple of EVs more than Greninja and I figured it might be more common with MegaMence around) and the rest in bulk. This leaves Lopunny very fast, moderately strong and surprisingly bulky - for example, max attack adamant Dragonite always fails to OHKO with Outrage, even with Stealth Rock on the field (I know Dragonite isn't a hugely relevant Pokemon but its Outrage is not weak).
Fake Out is probably the most unusual move on this set, and although I usually dislike the move I think it fits Lopunny very well. The biggest downsides of Fake Out in my eyes are that it robs the user of coverage and invites normal resists/immunities in for free. Lopunny rectifies both of these because it doesn't need coverage and HJK ensures rock/steel types rarely consider switching in, while Scrappy makes ghosts a terrible answer. In return, Fake Out allows Lopunny-M to beat basically any offensive Pokemon one-on-one by affording the extra bit of damage it needs to take on fighting resists. Latios is always 2HKOd by Fake Out + Frustration, Latias is with SR on the field (or a round of LO recoil), Greninja dies almost 100% of the time to straight Frustation with SR up but if it isn't Fake Out allows you kill it anyway, Gengar dies to Frustration, Sceptile-M dies to HJK (and you always survive 252 neutral nature Leaf Storm if SR is not up), Azumarill is easily 2HKOd by Frustration if it switches in, etc. It's actually mind boggling how good this Pokemon is - it reminds me of the way Manectric-M dismantles teams in the endgame, except it can do it in the mid-game instead.
The other three moves are fairly self explanatory - fairly strong STABs (Lopunny-M hits far harder than Manectric-M purely due to attack base power, despite their similar attacking stats) and Baton Pass for momentum, trapping, etc. Because of Fake Out + Baton Pass + massive speed, Lopunny-M almost always leads off the game very well - attacking leads are disposed of before they can do anything while against bulkier leads you can get a hit in while they set up SR and then Baton Pass to an appropriate wallbreaker.
Here's a fun replay of the set completely destroying run-of-the-mill offense.
